General Principles:
1. Response to diuretics tend to be an "all or none" phenomenon. That is, there needs to be a threshold concentration of diuretic in the tubule of the kidney in order to get an adequate diuretic response. In states of diuretic resistance (congestive heart failure, renal failure, neprhrotic syndrome) one may need to have the patient on a fairly high dose in order to get an adequate diuretic response.
2. A practical formula for inital dose of furosemide (cited NEJM 2009; 361: 2153-64) in patients with GFR < 30-40 is (patient age + BUN) = total daily dose furosemide split bid.
(In many patients, this actually may be a pretty high initial dose, so even though this is cited in NEJM, it may be reasonable to start a bit lower)
3. Salt restriction is very important in volume overloaded states and is a common cause of "diuretic resistance"
4. Patients on high dose loop diuretics (> 160 mg furosemide/day) may develop diuretic resistance. In this setting, it may be reasonable to add a thiazide diuretic to potentiate diuresis, especially in fluid overloaded states. A common initial dose would be metolazone 2.5 mg daily, but doses as high as 5 mg BID have been used.
5. Bumex (Bumetanide) is a generic loop diuretic that is pretty much the same as furosemide but tends to have better bioavailability and signifcantly lower incidence of ototoxcity at high doses. Consider using it instead of furosemide in patients who develop "diuretic resistance" when they get volume overloaded. 1 mg bumetanide = 40 mg furosemide, in advanced renal failure, the conversion factor is about 1 mg bumetanide = 20 mg furosemide
6. In patients with significant diuretic induced hypokalemia, consider addition of spirinolactone 12.5 -25 mg daily. This is especially indicated in those with class III/IV systolic CHF or resistant HTN, but should be done very cautiously in those with creat > 2.0
7. This is a patient handout for outpatient diuretic sliding scale:
A suggested algorithm for a PRN increase in furosemide dose is as follows:
Usual Furosemide dose: Increase by this amount PRN weight gain
Furosemide 20 mg AM daily: Extra 20 mg in PM
Furosemide 40 mg AM daily: Extra 40 mg in PM Furosemide 80 mg AM daily: Extra 40 mg in PM. If needed increase to extra 80 mg in PM Furosemide 20 mg Twice daily: Extra 20 mg in AM
Furosemide 40 mg Twice daily: Extra 40 mg in AM Furosemide 80 mg Twice daily: Extra 40 mg at noon. If needed increase to extra 80 mg at noon.
This page has been edited 4 times. The last modification was made by - oliverzgraham on Feb 22, 2010 11:42 am
1. Response to diuretics tend to be an "all or none" phenomenon. That is, there needs to be a threshold concentration of diuretic in the tubule of the kidney in order to get an adequate diuretic response. In states of diuretic resistance (congestive heart failure, renal failure, neprhrotic syndrome) one may need to have the patient on a fairly high dose in order to get an adequate diuretic response.
2. A practical formula for inital dose of furosemide (cited NEJM 2009; 361: 2153-64) in patients with GFR < 30-40 is
(patient age + BUN) = total daily dose furosemide split bid.
(In many patients, this actually may be a pretty high initial dose, so even though this is cited in NEJM, it may be reasonable to start a bit lower)
3. Salt restriction is very important in volume overloaded states and is a common cause of "diuretic resistance"
4. Patients on high dose loop diuretics (> 160 mg furosemide/day) may develop diuretic resistance. In this setting, it may be reasonable to add a thiazide diuretic to potentiate diuresis, especially in fluid overloaded states. A common initial dose would be metolazone 2.5 mg daily, but doses as high as 5 mg BID have been used.
5. Bumex (Bumetanide) is a generic loop diuretic that is pretty much the same as furosemide but tends to have better bioavailability and signifcantly lower incidence of ototoxcity at high doses. Consider using it instead of furosemide in patients who develop "diuretic resistance" when they get volume overloaded. 1 mg bumetanide = 40 mg furosemide, in advanced renal failure, the conversion factor is about 1 mg bumetanide = 20 mg furosemide
6. In patients with significant diuretic induced hypokalemia, consider addition of spirinolactone 12.5 -25 mg daily. This is especially indicated in those with class III/IV systolic CHF or resistant HTN, but should be done very cautiously in those with creat > 2.0
7. This is a patient handout for outpatient diuretic sliding scale:
This is a simplified (but a bit more crowded) one page handout for outpatient diuretic sliding scale:
A suggested algorithm for a PRN increase in furosemide dose is as follows:
Usual Furosemide dose: Increase by this amount PRN weight gain
Furosemide 20 mg AM daily: Extra 20 mg in PM
Furosemide 40 mg AM daily: Extra 40 mg in PM
Furosemide 80 mg AM daily: Extra 40 mg in PM. If needed increase to extra 80 mg in PM
Furosemide 20 mg Twice daily: Extra 20 mg in AM
Furosemide 40 mg Twice daily: Extra 40 mg in AM
Furosemide 80 mg Twice daily: Extra 40 mg at noon. If needed increase to extra 80 mg at noon.
This page has been edited 4 times. The last modification was made by -